The present invention relates to crop balers, such as large rectangular balers, equipped with infeed cutter apparatus immediately behind the pickup header to reduce incoming crop materials into smaller pieces before the materials are packed into a bale by other mechanism in the machine. More particularly, the present invention pertains to a way of dramatically increasing the throughput of such balers notwithstanding the presence of such cutter apparatus within the flow path of crop materials through the baler.
It is known in the art to provide a large rectangular baler with cutter apparatus adjacent the leading end of a tubular passage through which picked up crop materials are compacted into charges and then delivered into the main baling chamber of the machine. See for example U.S. Pat. No. 6,298,646 assigned to the assignee of the present invention, which is hereby incorporated by reference into the present specification.
One problem encountered with cutter balers of this type relates to the fact that the main baling chamber, which is generally horizontally disposed and extends fore-and-aft in line with the path of travel of the machine, is typically narrower than the width of the crop windrow picked up by the wide pickup header of the machine. This necessitates consolidating the over-width stream of picked up materials prior to its entry into the narrower transfer passage that leads to and corresponds in width to the baling chamber. Cutter apparatus positioned in the mouth or inlet of the passage is thus presented with a large consolidated mass of materials to deal with, rather than a thin, spread-out stream.
While various methods of consolidating the picked up materials into a narrower stream have been used in cutter balers over the years, prior efforts in this regard have not been totally satisfactory, often resulting in reduced throughput from a machine that, without the cutter apparatus, is capable of significantly greater productivity. Productivity shortfalls have been suffered not only in high moisture conditions on the one hand and light, dry crop conditions on the other, but in ideal crop conditions as well.
Prior to the present invention, one line of conventional wisdom was that the presence of the cutter apparatus in the flow passage created a type of restriction in the flow path that simply could not handle the extra volume of materials created by the consolidating action of the pickup, even though the compacting and feeding mechanism disposed behind the cutter apparatus could handle that volume with relative ease. While lower stub augers positioned on opposite outboard sides of the inlet of the flow passage were quite successful in consolidating outer portions of the picked up windrow into fore-and-aft alignment with the inlet, there was a tendency for the center-gathered materials to simply bunch up and lose momentum at the mouth of the inlet rather than to flow smoothly into and through the cutter apparatus. Thus, it was thought that efforts should be concentrated in somehow relieving the choke point or restriction created by the cutter apparatus itself so that materials could more easily flow through the cutter. Focusing on the cutter and its confined space as the source of the problem, however, now appears to have been a mistake.
It has now been discovered that the problem lies not in the fact that the volume of materials presented to the cutter apparatus is large, but rather in the way such volume is presented. Generally speaking, in the present invention, instead of allowing the centrally gathered materials to boil up and lose momentum just ahead of the inlet and cutter apparatus, the center gathered materials are kept under control with an overhead confining force at the critical transition point in front of the cutter apparatus. In a preferred embodiment, this is accomplished by providing an overhead, downturning top auger that spans the full width of the pickup header above a pair of upturning stub augers on opposite sides of the inlet. Preferably, the cutter apparatus includes a downturning rotor having an axis of rotation located just behind the inlet and with generally radially projecting prongs that reach out slightly through the inlet as they sweep down across front portion of their path of travel. Best results have been obtained where the top auger is low enough to keep the incoming flow of crop materials below the axis of rotation of the cutter rotor. Thus, instead of rejecting the inflowing materials, the rotor prongs moving downwardly and rearwardly in a lower quadrant of their path of travel tend to readily accept the materials and move them through the cutting zone of the passage. Even though the auger flighting on the full length top auger is not generally considered to be particularly effective in feeding crop materials laterally of the auger, in this particular application, and by positioning the auger relatively low with respect to the cutter rotor, the flighting seems to have just enough ability to keep the materials moving laterally through the transition zone and into the grasp of the rotor to provide a relatively""smooth, constantly moving inflow of materials to the cutter rotor and a consequent significant increase in overall throughput of the machine. Preferably, the top auger is adapted to move the materials it engages toward the center at a faster transverse speed than the stub augers so that a kind of separating action is obtained by the top auger.